The Ordos Plateau, also known as the Ordos Basin, the Ordos, or the Shaan-Gan-Ning Basin, is a highland sedimentary basin in parts of northernmost China with an elevation of 1,000–1,600 m (3,300–5,200 ft), and consisting mostly of land enclosed by the "Ordos Loop", a northerly rectangular bend of the Yellow River. It is China's second largest sedimentary basin (after the Tarim Basin) with a total area of 370,000 km2 (140,000 sq mi). The Ordos includes territories from five provinces: Shaanxi, Gansu, Ningxia, Inner Mongolia, and a thin fringe of Shanxi (western border counties of Xinzhou, Lüliang and Linfen), but is demographically dominated by the former three, hence the area is sometimes also called the "Shaan-Gan-Ning Basin". The basin is bounded in the east by the Lüliang Mountains, north by the Yin Mountains, west by the Helan Mountains, and south by the Huanglong Mountains, Meridian Ridge and Liupan Mountains.
The name "Ordos" (Mongolian: ) comes from the orda, which originally means "palaces" or "court" in Old Turkic. The seventh largest prefecture of Inner Mongolia, Ordos City, is similarly named due to its location within the Ordos Loop.
The Ming Great Wall cuts southwesterly across the center of the Ordos region, roughly separating the sparsely populated north (or "upper Ordos", which is actually lower in elevation than the "lower Ordos" south) — considered the Ordos proper — from the agricultural south (or "lower Ordos", i.e. northern part of the Loess Plateau). The north Ordos consists mainly of the arid Ordos Desert (subdivided into the Mu Us and Kubuqi deserts), which is administered by Inner Mongolia's Ordos City, but the floodplains along the banks of Ordos Loop's northern bends are fertile grasslands historically known as the Hetao Plains ("river loop" plains), which is subdivided into the "west loop" (within Ningxia) and "east loop" (within Inner Mongolia, further divided into "front loop" and "back loop") sections. The Inner Mongolian cities of Hohhot (provincial capital), Baotou, Bayannur and Wuhai (its third, fourth, eighth and eleventh most populous prefectures respectively), and all of Ningxia's cities except Guyuan, are all located on these riverside plains along the Hetao region. Throughout Chinese history, the Hetao region was of major strategic importance and therefore hotly contested against various Eurasian nomads such as Di and Rong (Shang and Zhou dynasties), Xiongnu (Qin and Han dynasty), Rouran (Northern Wei), Eastern Göktürk (Sui and Tang dynasty) and Mongols (Ming dynasty).
